Microlearning Potential Bug

We've noticed that Rise is occasionally modifying the background color behind some images to display a color that isn't being directly called for, at least not in that location.
In the attached screenshot of the issue, you can see a side-by-side view of this while in edit mode (on the left), and from the share link (on the right). While in edit mode, the section has the default value for white: #ffffff. However, when you preview the course, it changes to navy blue. That blue is used elsewhere in the course, as seen in the section below, just not here. The background is also only partially changed, giving it a layered effect, with it changing to white part of the way through the image.
This is a standard block template that we use in most of our eLearning courses. It only does this in the Microlearning courses we're trying to build.
We've found a workaround solution by simply manually keying in #ffffff. But if the default is already set to that, and this is only randomly happening, it makes it seem a bit glitchy.

Any thoughts on what might be going on if it's not a bug?